1. Field of the Invention
Embodiments of the present invention relate to a liquid crystal display and corresponding method for providing low power consumption in a self screen mode.
2. Description of the Related Art
Liquid crystal displays display an image by controlling a light transmittance of a liquid crystal layer through an electric field in response to a video signal. The liquid crystal display is also a flat panel display device having advantages such as a thin profile, a small size, and low power consumption. Thus, liquid crystal displays are used in personal computers such as notebook PCs, office automation equipment, audio/video equipment, and the like.
In addition, an active matrix type liquid crystal display includes a switching element formed in each liquid crystal cell. Therefore, the active matrix type liquid crystal display is advantageous for displaying a moving picture, because the switching elements can be actively controlled. Further, a thin film transistor (TFT) is used in the switching element of the active matrix type liquid crystal display.
In more detail, and with reference to FIG. 1, an active matrix type liquid crystal display converts digital video data into an analog data voltage based on a gamma reference voltage to supply the analog data voltage to a data line DL, and at the same time, to supply a scan pulse to a gate line GL. Hence, a liquid crystal cell Clc is charged to a data voltage. For the above-described operation, a gate electrode of a TFT is connected to the gate line GL, a source electrode of the TFT is connected to the data line DL, and a drain electrode of the TFT is connected to a pixel electrode of the liquid crystal cell Clc and an electrode at one side of a storage capacitor Cst. Further, a common voltage Vcom is supplied to a common electrode of the liquid crystal cell Clc.
When the TFT is turned on, the storage capacitor Cst is charged to the data voltage received from the data line DL to keep a voltage of the liquid crystal cell Clc constant. The TFT is turned on when the scan pulse is supplied to the gate line GL, the TFT is turned on. Thus, a channel is formed between the source electrode and the drain electrode of the TFT, and a voltage on the data line DL is supplied to the pixel electrode of the liquid crystal cell Clc. In addition, when an arrangement state of liquid crystal molecules of the liquid crystal cell Clc changes by an electric field between the pixel electrode and the common electrode, incident light is modulated.
However, the related art liquid crystal display has the following problems. First, when the liquid crystal display is used as a television, for example, and is mounted on a wall, the display has a dark or black appearance when it is not used. Further, many liquid crystal displays are large in size, and thus the liquid crystal display has an unattractive appearance when it is not being used, especially when the display is used in a home, office, work environment, etc. In addition, the amount of power consumption used by display has greatly increased especially with large sized and high definition (HD) liquid crystal displays. The high power consumption disadvantageously affects liquid crystal displays.